In recent years, a number of new telephone service features have been provided by an Advanced Intelligent Network (AIN). The AIN evolved out of a need to increase the capabilities of the telephone network architecture in order to meet the growing needs of telephone customers or users. The AIN architecture generally comprises two networks, a data messaging network and a circuit-switched, trunked communications network. The trunked communications network handles voice and data communications between dispersed network locations, while the data messaging network is provided for controlling operations of the trunked communications network.
A privacy screening service is a service that enables a subscriber to screen incoming calls. The privacy screening service provides information to the called party (in this case, the subscriber to the privacy screening service) that allows the subscriber to make an informed decision as to whether or not to answer a call. For example, a subscriber may (and typically does) use the privacy screening service to block all unidentified calls from being terminated (connected). Calls can be unidentified because the sending telecommunications carrier does not forward the calling telephone number to the receiving telecommunications carrier (because the sending carrier's equipment is incapable of sending the calling telephone number or because the call is coming from another area), or because the calling telephone number is marked “private”.
Private telephone numbers are telephone numbers that block services such as “caller ID” that would otherwise identify the caller to the called party. A caller can request a private number so calls made from that line are always marked private or a caller can block the display of the telephone number for a particular telephone call by dialing a code such as *67.
In telephone systems that offer private numbers and a privacy screening service to its customers, an unidentified call to a subscriber with the privacy screening service cannot be completed automatically unless the subscriber authorizes the system to override the privacy screening service. In order for the subscriber to receive such a call, the privacy screening service forces the caller to make a selection that either allows the calling telephone number to be displayed or records a message from the caller. When the call is terminated, the privacy screening service subscriber will typically be notified that the privacy screening service has been invoked, and either the calling telephone number will be displayed or the recorded message will be played. The called party can then chose to respond to the call as he sees fit.
Typically, customers subscribe to a privacy screening system to avoid calls from unidentified callers such as telemarketers, who frequently employ private telephone numbers. Frequently, telemarketers canvass an area by using automatic dialers programmed to dial a list of telephone numbers. For example, an automatic dialer may be programmed to dial all the numbers between 0000 and 9999 in a targeted exchange. When the automatic dialer detects that a call has been answered by a person, the call is transferred to an available telemarketer.
Telecommunication systems typically indicate that a dialed number is disconnected or vacant (unassigned) by directing the call to an “intercept” routine. Typically, for example, when a call is made to a disconnected number, a standard information tone (SIT) is played, followed by a message such as: “I'm sorry. The number you have called has been disconnected. Calls are being taken by . . . ” (or “No further information is available about . . . ”). The tone that indicates that a number has been disconnected is a standardized series of three tones of a particular frequency and duration agreed upon by telecommunication companies. Similarly, the tone that indicates that a number is not in use is another series of three tones of particular frequency and duration. Automatic dialers frequently are programmed to detect and recognize these SITs and to put disconnected and vacant numbers identified by the SITs on a “Do Not Call” list.
As described above, although privacy screening helps to reduce the number of unwanted calls received by a subscriber, subscribers to a privacy screening service can receive unwanted calls. It would be helpful if there were a way to further reduce the number of unwanted calls terminated.